JPS6184527A - light sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention relates to a method for detecting the amount of light received by each light-receiving element of an optical sensor, especially when an optical lens is used to capture external light in an optical sensor, particularly a one-dimensional image sensor. This invention relates to an optical sensor that has been improved to have a nearly proportional relationship with external light.

[Conventional technique] When a light sensor is formed by arranging a plurality of light-receiving elements in parallel and guides the light of a subject through an optical lens to the light-receiving surface of the light sensor, the light from the subject located close to the optical axis of the optical lens is The amount of light from objects located far from the optical axis is large, and the amount of light from objects located far from the optical axis is small and reaches the optical sensor. That is, when an object is read by an optical sensor, the light amount distribution on the optical sensor becomes non-uniform.

If there is a distribution of light intensity on the optical sensor in this way, the output of the electrical signal will differ depending on the amount of light, so the optical sensor will not be able to faithfully reproduce the brightness and darkness of the subject.

Since the light-receiving elements having the same element area as the conventional optical sensor 4 are uniformly arranged in parallel to form the light-receiving surface, the light intensity distribution on the optical sensor becomes uneven, resulting in an output that does not correspond to the brightness and darkness of the subject. This is often an obstacle in practice.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and corrects the non-uniformity of the amount of light on the photosensor caused by the optical lens by changing the element area of the light receiving element. , so that a uniform sensor output can be obtained.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the photosensor l is formed with a plurality of light-receiving elements 3 arranged in parallel, and captures a subject A-B with an optical lens, forming an image A'-B' on the light-receiving surface of the photosensor.
It is designed to give rise to The light receiving element 3 forms an image A'
A photoelectric element converts and outputs an electric signal according to the light of -B', and each has an element area S. Here, the element area S refers to the effective area of the light-receiving surface of the light-receiving element 3-, and in the light-receiving elements of conventional photosensors, this element area S is always the same, and the performance is the same. There is. Therefore, when the object A-B is imaged on the optical sensor 1 using an optical lens, the characteristics of the optical lens 2 are generally as shown in Fig. 2.
At the ends of ' and B', the amount of light Q becomes smaller toward the shark in the center.

Such a phenomenon cannot be avoided as long as optical lenses are used.

The present invention is to change the element area S of each light receiving element according to the imaged light t:Q generated by the optical lens 2 in all areas on the photosensor l so that QXS is constant. It is characterized by

A method of changing the element area S to achieve this purpose is, for example, as shown in Fig. 3, by keeping the width d of the light receiving element 3 constant and changing the length to adjust the element area to the light intensity distribution on the optical sensor. It may be changed depending on the situation, or the length may be kept constant and the width may be changed as shown in Fig. 4.

[Effects of the Invention] Since the present invention is configured as described above, it is possible to eliminate non-uniformity in the light amount distribution on the optical sensor caused by the optical lens. As a result, when a subject is taken in by an optical lens and its image is read by an optical capacitor, it can be detected by a light receiving element as an output of an electrical signal corresponding to the brightness or darkness of the subject.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the optical system of the optical sensor according to the present invention, FIG. 2 is a light amount distribution diagram of imaging in the optical system of FIG. 1,
3 and 4 respectively show front views of the light receiving surface of the optical sensor according to the embodiment of the present invention. In the figure, 1 is an optical sensor, 2 is an optical lens, and 3 is a light receiving element. Figure 1 Optical lens 2 Optical sensor 1 Figure 3. figure

Claims (1)

[Scope of Claims] 1. In an optical sensor configured to form a light-receiving surface by arranging a plurality of light-receiving elements in parallel, and to read a subject with an optical lens and form an image on the light-receiving surface, the element area of the light-receiving element An optical sensor in which the element area of each light-receiving element is changed according to the amount of light received so that S×D is approximately constant, where S is the amount of light received and Q is the amount of light received. 2. The optical sensor according to claim 1, wherein the element area is changed by changing the spacing between the light receiving elements. 3. The optical sensor according to claim 1, wherein the spacing between the light-receiving elements is constant, and the element area is changed by changing the width of the light-receiving elements.